Exchange bias effect and anisotropy analysis of FM/AF bilayers

The exchange bias effect of NiFe-MnPd bilayers and a new system Fe-MnPd bil ayers was analyzed. Through fitting the in-plane angular dependence of the exchange bias field H-ex and the coercivity H-c obtained by magneto-optical Kerr effect (MOKE), the in-plane anisotropies of the two systems were obta ined. We found large additional higher order anisotropies (uniaxial and fou r-fold) in the system due to ferromagnet (FM)-antiferromagnet (AF) exchange bias coupling. These anisotropies show a linear dependence on the inverse FM thickness indicating their interfacial origin caused by exchange bias ef fect. The thickness dependence of the exchange bias fields H-ex and the coe rcivity H-c also exhibited a linear dependence on the inverse FM layer thic kness. (C) 2000 Elsevier Science S.A. All rights reserved.